The Leuchter report

13.79 The reason why Irving initially denied the existence of gas chambers at Auschwitz was, as has been seen, the Leuchter report. I have summarised in some detail the findings made by Leuchter at paragraphs 7.82 to 7.89 above. I will not repeat myself. I have also set out at paragraphs 7.104 to 7.108 above the reasons why van Pelt on behalf of the Defendants dismissed the Leuchter report as flawed and unreliable. Those reasons were put to Irving in cross-examination. It is a fair summary of his evidence to say that he accepted the validity of most of them. He agreed that the Leuchter report was fundamentally flawed. In regard to the chemical analysis, Irving was unable to controvert the evidence of Dr Roth (summarised at paragraph 7.106 above) that, because the cyanide would have penetrated the brickwork and plaster to a depth of no more than one tenth of the breadth of a human hair, any cyanide present in the relatively large samples taken by Leuchter (which had to be pulverised before analysis) would have been so diluted that the results on which Leuchter relied had effectively no validity. What is more significant is that Leuchter assumed, wrongly as Irving agreed, that a greater concentration of cyanide would have been required to kill humans than was required to fumigate clothing. In fact the concentration required to kill humans is 22 times less than is required for fumigation purposes. As indicated in paragraph 7.105 above, and as Irving was constrained to accept, Leuchter's false assumption vitiated his conclusion. Irving conceded the existence of many other factual errors in the Leuchter report.

13.80 In the light of the evidence of van Pelt and Irving's answers in cross-examination, I do not consider that an objective historian would have regarded the Leuchter report as a sufficient reason for dismissing, or even doubting, the convergence of evidence on which the Defendants rely for the presence of homicidal gas chambers at Auschwitz. I have not overlooked the fact that Irving claimed that Leuchter's findings have been replicated, notably in a report by Germar Rudolf. But that report was not produced at the trial so it is impossible for me to assess its evidential value.